Abstract
2, 4-Dichlorophenoxyacetic acid (2, 4-D) is a board-leaf selective herbicide and globally used in agricultural activities. Complexation mode, spectroscopic investigations and biological properties of complexes formed between 2,4-D (C6H3Cl2OCH2 . COOH ; HL) with Zn(II) Cu(II) , Ni(II) Co(II) and Mn(II) metal ions were investigated. To characterize the binding mode between 2, 4-D and the metal ions, many physicochemical approaches were employed. The complexes obtained are characterized quantitatively and qualitatively by using micro elemental analysis, FTIR spectroscopy, UV-Vis spectroscopy, H-1-NMR, and magnetic susceptibility measurements. Results of these approaches suggested that the gross formula of the complexes obtained with the metal ions were [ZnL2](2H(2)O (1) , [CuL2(H2O)(2) (2), [NiL2](3H(2)O (3), [CoL2(H2O)(2)] (4) , and [MnL2(H2O)(2)] (5). In all complexes, two L anion were coordinated the metal ion by their bidentate carboxylate groups. From the spectral study, all the complexes obtained as monomeric structure and the metals center moieties are six-coordinated with octahedral geometry except Ni (II) and Zn(II) complexes which existed as a tetrahedral and square pyramidal geometry respectively. The complexes were screened in vitro against several microbes (fungi and bacteria) using Kirby-Bauer disc diffusion method, and data has demonstrated that complex 3 showed excellent antifungal activity.